1. Field of the Invention
This invention relates in general to a method and apparatus for addressing and testing multiple disk assemblies, and more particularly, to a method and apparatus for addressing a plurality of AT Attachment, Integrated Drive Electronics (ATA/IDE) drive assemblies from a single PC/AT.
2. Description of Related Art
It is desirable to test Integrated Drive Electronics (IDE) disk drives using the PC/AT Industry Standard Architecture (ISA) bus. This is the natural bus for the IDE disk drive and, therefore, the most effective way to evaluate disk drive performance. However, the standard AT Attachment (ATA) protocol of addressing IDE disk drives via the PC/AT limits the number of drives which may be addressed to two. Because of this limitation, a PC/AT mother board can test only two drives at a time. This poses cost problems for high volume testing of ATA/IDE drive assemblies in a manufacturing environment.
If the standard method of addressing ATA/IDE drive assemblies is used, then a PC/AT is required for every two drives under test. In order to support high volume production testing, a considerable capital investment would be consumed in PC/AT mother boards and the required hardware needed to support each mother board. This includes memory chips, add on cards, power supplies, and mounting hardware. Further, due to the high numbers of PC/AT based testers required, additional floor space and power requirements are directly affected.
Many approaches have been used for testing disk drives. For example, U.S. Pat. No. 4,725,968, issued Feb. 16, 1988, to Baldwin et al., entitled "DISK DRIVE TESTING METHOD AND APPARATUS", and incorporated herein by reference, discloses a disk drive testing apparatus which provides substantially automatic cycling through various tests of disk drive units. A graphical display is provided on a screen to the operator to allow the operator to determine whether the disk drive is performing in or out of specifications which may be read into the apparatus from an EEPROM memory module. The operator can cycle through a preselected series of tests on the drive unit. The tester is controlled by a microcomputer central processing unit to cycle through the tests and to provide a display on the screen for selected tests. The tester also provides an analysis of the probability of disk reading and writing errors and displays a graph illustrating the likelihood that data bit timing from the disk drive will remain within selected window margins over long periods of time. However, the ISA bus is not used and only one disk drive may be tested at any given time.
U.S. Pat. No. 4,438,761, issued Sep. 7, 1982, to James K. Berger, assigned to Pioneer Research, Inc., entitled "PORTABLE FIELD TEST UNIT FOR COMPUTER DATA AND PROGRAM STORAGE DISC DRIVE", and incorporated herein by reference, discloses a portable, programmable, microprocessor-controlled, universal field test unit capable of performing functional tests. The unit capable of carrying out special test programs, standard diagnostic programs, and formatting disc packs with many different formats. Individual instructions may be executed in the unit, or it may be run automatically under program control. Programs may be created by the actuation of the operation keys and numeric keys, or they may originate from a pre-programmed memory. However, the ISA bus is not used and only one disk drive may be tested at any given time.
U.S. Pat. No. 4,949,036, issued Aug. 14, 1990, to Bezinque et al., assigned to Seagate Technology, Inc., entitled "DISC DRIVE ERROR MAPPING USING THRESHOLD COMPARISON METHODS", and incorporated herein by reference, discloses an apparatus and method for testing a variety of hard disk drives which includes a computer connected to a control board and an interface board. The interface board is connected to a testing board. The hard disk drive is connected to the control board and testing board. The hard disk is tested by first erasing a track of data bits at full write current in one direction or polarity and second erasing the track at minimal write current in the opposite direction. The track is read and compared to a predetermined threshold and any level exceeding the threshold is considered defective. However, the ISA bus is not used and only one disk drive may be tested at any given time.
U.S. Pat. No. 5,361,346, issued Nov. 1, 1994, to Panesar et al., assigned to Santa Monica Pioneer Research, Inc., entitled "PORTABLE TESTER (QUALIFIER) FOR EVALUATING AND TESTING SCSI INTERFACE MAGNETIC DISC DRIVES IN ACCORDANCE WITH ANSI SCSI-A AND SCSI-2 DEFINITIONS", and incorporated herein by reference, discloses a programmable menu driven qualifier designed to test and evaluate direct access and sequential access SCSI devices. The testing is carried out in accordance with ANSI SCSI-1 and ANSI SCSI-2 definitions. A completely menu driven qualifier is used to execute all commands with a single keystroke of the keyboard. The qualifier uses a simple built-in concept which allows an operator quickly to become familiar with an SCSI protocol and command structure. Generally, the SCSI bus allows multiple CPUs to be coupled up to multiple disks. However, a SCSI controller card is required. Thus, ATA/IDE drive assemblies are not compatible.
Japanese Patent 4155670 invented by Nishizawa Shigenori, entitled "TESTING SYSTEM FOR SCSI DEVICE", and incorporated herein by reference, also discloses a device for testing SCSI disk drives. As mentioned above, a SCSI bus allows multiple CPUs to be coupled up to multiple disks, but a SCSI controller card is required and ATA/IDE drive assemblies are not compatible.
U.S. Pat. No. 4,641,207, issued Feb, 3, 1987, to Green et al., entitled "DIAGNOSTIC DEVICE AND METHOD FOR EXAMINING THE OPERATION OF A DISK DRIVE", and incorporated herein by reference, discloses an external diagnostic device for examining the operation of a disk drive. The device is coupled to input terminals and output terminals of the drive and operates in a selected one of several modes at a given time. However, the ISA bus is not used and only one disk drive may be tested at any given time.
U.S. Pat. No. 4,967,155, issued Oct. 30, 1990, to Vernon P. Magnuson, assigned to Micropolis Corporation, entitled "ENVIRONMENTALLY CONTROLLED MEDIA DEFECT DETECTION SYSTEM FOR WINCHESTER DISK DRIVES", and incorporated herein by reference, discloses an environmentally controlled media defect detection system for Winchester disk drives. The system includes a testing cabinet which is divided into two sections. The first section is maintained at an environmentally controlled elevated temperature for testing Winchester disk drives at elevated operational temperatures above ambient room temperatures. The second section is thermally insulated from the first section and contains a plurality of disk drive test units. One test unit is coupled to each Winchester disk drive being tested, and the test units have the ability to apply digital signals to the drive for writing and reading signals onto tracks of the drives, determining malfunctions, and imperfections in the disk media of the hard disk drive systems. Although multiple disk drives may be tested, the ISA bus is not utilized and thus multiple ATA/IDE drive assemblies may not be tested using a single PC/AT.
U.S. Pat. No. 4,888,549, issued Dec. 19, 1989, to Wilson et al., assigned to Wilson Laboratories, Inc., entitled "SYSTEM FOR TESTING INDIVIDUALLY A PLURALITY 0F DISK DRIVE UNITS", and incorporated herein by reference, discloses a tester for storage peripheral devices. The tester comprises a test module which contains one or more ports. The storage peripheral device under test is placed into a carrier which is in turn inserted into the port. The carrier preferably includes a base comprised of a printed circuit board, a front panel, a frame and electronics and electronic connectors. The unit under test is connected to the base via the electronic connectors. The carrier is inserted into mating engagement with the test module. Environmental control is achieved by varying the amount of air flow through the test ports. Again, multiple disk drives may be tested, a means of using the ISA bus to test multiple ATA/IDE drive assemblies using a single PC/AT is not disclosed.
In addition to the shortcomings exhibited by the approaches discussed above, vendor IDE testers typically will test only a master or slave. For example, vendor IDE testers may use two parallel IDE channels which allows testing of two masters and two SLAVEs. However, this arrangement requires the use of a non-ISA bus. Other IDE testers have a single controller for each IDE drive under test. However, these also require the use of a non-ISA bus. Another method of testing disk drives buffers the PC/AT ISA bus out to a remote card which decodes the bus. A custom IDE controller then is used to communicate to the IDE drive. Further, if the MASTER/SLAVE addressing method is used, then the manufacturing operator is required to correctly set the option block jumper. This requires operator time and may result in errors in the setting of the option block which will degrade first pass test yield. Thus, the absence of a system that can address multiple ATA/IDE drive assemblies from a single PC/AT leads to a relatively high cost per test point.
Yet, the PC/AT CPU and I/O to each drive is idle much of the time since a substantial part of drive assembly testing is done via special code or self test. Thus, if only two drive assemblies are addressed, then PC/AT CPU utilization is very low. This CPU idle time could be used to initiate and test other drive assemblies.
It can seen then that there is a need for a disk drive tester that results in much lower per point cost for testing ATA/IDE drive assemblies.
It can also be seen that there is a need for a disk drive tester that can test multiple ATA/IDE disk drives using a single PC/AT computer.
Finally, it can also be seen that there is a need for an IDE disk drive tester which utilizes the substantial CPU and I/O idle time available during the testing of drive assemblies.